Aplikovatelnost PENT testu pro novou generaci potrubí z PE

The applicability of the Pennsylvania Notch Test for a new generation of PE pipe grades

journal article - other

en

The failure mode termed long time brittle failure (due to slow crack growth – SCG) limits the lifetime of plastic pipes. There are now two main accelerated tests (PENT and FNCT) that enable us to estimate the lifetime of HDPE used in plastics pipes. For unimodal grades, the time to failure corresponding to these accelerated tests is about ten hours, for bimodal grade PE 100 it is roughly a thousand hours and for the new PE 100 RC grade is greater than 1 year. For the HDPE pipes grade with higher resistance against SCG, some modification or, alternatively, new tests should be developed that make it possible even for these materials to obtain the results required in a relatively short time. In this contribution we focus mainly on the PENT test and the possibility of the utilization of a structural analysis as well as a numerical approach for prediction of the lifetime of a new generation of PE grades.

Tento příspěvek obsahuje popis a výsledky zrychlených experimentů, které se používají k testování polymerních materiálů. Na základě těchto výsledků a numerické simulace lze odhadnout životnost polymerních materiálů používaných u potrubí pro rozvod kapalin a plynů.

The failure mode termed long time brittle failure (due to slow crack growth – SCG) limits the lifetime of plastic pipes. There are now two main accelerated tests (PENT and FNCT) that enable us to estimate the lifetime of HDPE used in plastics pipes. For unimodal grades, the time to failure corresponding to these accelerated tests is about ten hours, for bimodal grade PE 100 it is roughly a thousand hours and for the new PE 100 RC grade is greater than 1 year. For the HDPE pipes grade with higher resistance against SCG, some modification or, alternatively, new tests should be developed that make it possible even for these materials to obtain the results required in a relatively short time. In this contribution we focus mainly on the PENT test and the possibility of the utilization of a structural analysis as well as a numerical approach for prediction of the lifetime of a new generation of PE grades.

PENT test, odhad životnosti, HDPE, růst trhliny, lomová mechanika

PENT test, lifetime prediction, HDPE, Slow crack growth, Fracture mechanics

2012

18.09.2012

0142-9418

32

1

106–114

9